Fan

ABSTRACT

A fan includes a first motor, a second motor, a rotating shaft and a fan blade. The first motor includes a first coil. A first current flows through the first coil when the fan is electrified. The second motor includes a second coil. A second current flows through the second coil when the fan is electrified. The fan blade is affixed to the rotating shaft. The first motor and the second motor drive the rotating shaft to rotate the fan blade when the fan is electrified.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 201410707544.1 filed in China on Nov. 27, 2014, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The disclosure relates to a fan. More particularly, the disclosure relates to a fan with two motors and a rotating shaft.

2. Description of the Related Art

A heat-dissipating fan used for an electronic device is usually driven by a motor. However, when the heat-dissipating fan is driven to dissipate the heat generated by the electronic device, an electrical current passes through a coil of the motor, and the coil is heated gradually due to the electrical current. If the coil is at a high temperature for a long time, the insulating sleeve of the coil may be decayed or melted, and cause damages to the heat-dissipating fan. To avoid above problem, a user usually combine two heat-dissipating fans with each other as a single heat-dissipating fan set. When one of the two heat-dissipating fans fails, the other heat-dissipating fan can be still working for the electronic device, to dissipate the heat.

However, since the single heat-dissipating fan set is a combination of two heat-dissipating fans, the single heat-dissipating fan comprises two rotating shafts and two fan blades. Accordingly, the volume of the single heat-dissipating fan is increased. Additionally, when the two heat-dissipating fans work at the same time and the motor of one heat-dissipating fan fails, the heat dissipation efficiency of the single heat-dissipating fan decreases, the heat generated by the electronic device may be insufficient, and further cause damages to the electronic device.

SUMMARY OF THE INVENTION

One aspect of the disclosure provides a fan which comprises a first motor, a second motor, a rotating shaft and a fan blade. The first motor comprises a first coil. A first current flows through the first coil when the fan is electrified. The second motor comprises a second coil. A second current flows through the second coil when the fan is electrified. The fan blade is affixed to the rotating shaft. The first motor and the second motor drive the rotating shaft to rotate the fan blade when the fan is electrified.

Another aspect of the disclosure provides a fan which comprises a first motor, a second motor, a control circuit, a rotating shaft and a fan blade. The first motor comprises a first coil. The second motor comprises a second coil. The control circuit is for periodically switching a current value of a current flowing through the first coil and a current value of a current flowing through the second coil. The current value of the current flowing through the first coil is different from the current value of the current flowing through the second coil. The fan blade is affixed to the rotating shaft. The first motor and the second motor are for driving the rotating shaft to rotate the fan blade when the fan is electrified.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present disclosure and wherein:

FIG. 1 is a schematic view of a fan according to a first embodiment of the disclosure;

FIG. 2 is a schematic view of a fan according to a second embodiment of the disclosure; and

FIG. 3 is a schematic view of a fan according to a third embodiment of the disclosure.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawings.

Please refer to FIG. 1 which is a schematic view of a fan according to a first embodiment of the disclosure. As shown in FIG. 1, the fan 1 comprises a shell 10, a first motor 11, a second motor 12, a rotating shaft 13, a fan blade 14 and a fan frame 15.

An accommodation space 101 is formed inside the shell 10. In this embodiment, the whole structures of the shell 10 are integrally formed into a single unit. However, in other embodiments, for example, the shell 10 is a combination of two or more than two parts. Users can choose the shell 10 integrated by different parts according to their requirements.

The first motor 11 is disposed inside the accommodation space 101 of the shell 10 and comprises a first coil 111. In this embodiment, the first motor 11 is a direct current (DC) motor. The structure and principle of the DC motor are well-known by a person having ordinary knowledge in the art, such that they are not repeated herein.

The second motor 12 is also disposed inside the accommodation space 101 of the shell 10 and comprises a second coil 121. In this embodiment, the second motor 12 is also a DC motor. Similar to the first motor 11, the structure and principle of the DC motor are well-known by a person having ordinary knowledge in the art, such that they are not repeated herein.

The rotating shaft 13 pivots on the shell 10. The fan blade 14 is affixed to the rotating shaft 13. In this embodiment, the fan blade 14 is an axial fan blade. The fan frame 15 has an air inlet side 151 and an air outlet side 152. An airflow channel 153 is formed from the air inlet side 151 to the air outlet side 152.

The operation of the fan 1 is described as follows.

A first current is generated (for example, by a power supply or a control circuit) to flow through the first coil 111 of the first motor 11 when the fan 1 is electrified. In this embodiment, the first current is a rated current of the first motor 11. Additionally, a second current is generated to flow through the second coil 121 of the second motor 12 when the fan 1 is electrified. A current value of the second current is less than a current value of the first current, and a ratio of the current value of the second current to the current value of the first current is between 0% and 80%. In other words, a ratio of the current value of the second current to a current value of the rated current of the first motor 11 is between 0% and 80%.

For example, in one embodiment, when the current value of the first current flowing through the first coil 111 is A1 amperes (that is, the rated current of the first motor 11), the current value of the second current flowing through the second coil 121 is 0.55×A1 amperes. Furthermore, in other embodiments, when the current value of the first current flowing through the first coil 111 is A1 amperes, the current value of the second current flowing through the second coil 121 is 0 amperes (that is, only the first motor 11 works, and the second motor 12 does not work at the same time).

In this embodiment, when the fan 1 is electrified, the fan blade 14 is driven to rotate by the first motor 11, the second motor 12 and the rotating shaft 13 according to electromagnetic induction. The principle of electromagnetic induction is well-known by a person having ordinary knowledge in the art, such that it is not be repeated herein.

When the fan blade 14 is driven to rotate, at least one airflow F enters the fan frame 15 from the air inlet side 151, flows through the airflow channel 153, and finally leaves the fan frame 15 from the air outlet side 152.

Since the current value of the second current flowing through the first coil 111 is less than the current value of the first current flowing through the second coil 121, the first motor 11 and the second motor 12 can be prevented from both working at a high current at the same time. In one embodiment, only the first motor 11 works whereas the second motor 12 does not work, the energy of the second motor 12 can be saved. Therefore, the working efficiency and the life span of the fan 1 are improved.

Please refer to FIG. 2, which is a schematic view of a fan according to a second embodiment of the disclosure. As shown in FIG. 2, in this embodiment, the fan 1 comprises a shell 20, a first motor 21, a second motor 22, a rotating shaft 123, a fan blade 24, a control circuit 25 and a fan frame 26.

An accommodation space 201 is formed inside the shell 20. In this embodiment, the whole structures of the shell 20 are integrally formed into a single unit. However, in other embodiments, for example, the shell 20 is a combination of two or more than two parts. Users can choose the shell 20 integrated by different parts according to their requirements.

The first motor 21 is disposed inside the accommodation space 201 of the shell 20 and comprises a first coil 211. In this embodiment, the first motor 21 is an alternating current (AC) motor. The structure and principle of the AC motor are well-known by a person having ordinary knowledge in the art, such that they are not be repeated.

The second motor 22 is also disposed inside the accommodation space 201 of the shell 20 and comprises a second coil 221. In this embodiment, the second motor 22 is also an alternating current (AC) motor. Similar to the first motor 21, the structure and principle of the AC motor are well-known by a person having ordinary knowledge in the art, such that they are not be repeated.

The rotating shaft 23 pivots on the shell 20. The fan blade 24 is affixed to the rotating shaft 23. In this embodiment, the fan blade 24 is an axial fan blade. The control circuit 25 is electrically connected to the first motor 21 and the second motor 22. The fan frame 26 has an air inlet side 261 and an air outlet side 262. An airflow channel 263 is formed from the air inlet side 261 to the air outlet side 262.

Each component of the fan 2 is described as above-mentioned. Moreover, the operation of the fan 2 is described as follows.

The control circuit 25 is for periodically switching a current value of a current flowing through the first coil 211 of the first motor 21 and a current value of a current flowing through the second coil 221 of the second motor 22. Additionally, the current value of the current flowing through the first coil 211 and the current flowing through the second coil 221 are controlled by the control circuit 25 and different from each other.

In this embodiment, the control circuit 25 transmits a first current to the first coil 211 of the first motor 21 and a second current to the second coil 221 of the second motor 22 during a first time period. After the first time period, the control circuit transmits the first current to the second coil 221 of the second motor 22 and the second current to the first coil 211 of the first motor 21 during a second time period. Both spans of the first time period and the second time period are time periods when the fan blade rotates from 0 to 100000 revolutions. Moreover, a ratio of a current value of the second current to a current value of the first current is between 0% and 80%.

For example, when a rotation speed of the fan 2 is 2000 revolutions per minute (rpm), both the spans of the first time period and the second time period are 50 minutes. When the current value of the first current is A1 amperes, the second current is 0.45×A1 amperes. First, the control circuit 25 transmits the first current (A1 amperes) to the first coil 211 of the first motor 21, and transmits the second current (0.45×A1 amperes) to the second coil 221 of the second motor 22 during the first time period. After 50 minutes, the control circuit 25 transmits the second current (0.45×A1 amperes) to the first coil 211 of the first motor 21, and transmits the first current (A1 amperes) to the second coil 221 of the second motor 22 during the second time period during the second time period. The sum of the span of the first time period and the span of second time period is defined as a cycle, and the control circuit 25 repeats the cycle continuously.

In this embodiment, the fan blade 24 is driven to rotate by the first motor 21, the second motor 22 and the rotating shaft 23 when the fan 2 is electrified, such that at least one airflow F enters the fan frame 26 from the air inlet side 261, flows through the airflow channel 263, and finally leaves the fan frame 26 from the air outlet side 262.

Since the fan 2 comprises the control circuit 25 for periodically switching the current value of the current flowing through the first coil 211 of the first motor 21 and the current value of the current flowing through the second coil 221 of the second motor 22, the first motor 21 and the second motor 22 can be prevented from both working at a high current for a long time. Therefore, the working efficiency and the life span of the fan 2 is improved due to operation of the control circuit 25.

Please refer to FIG. 3, which is a schematic view of a fan according to a third embodiment of the disclosure. As shown in FIG. 3, in this embodiment, the fan 3 comprises a shell 30, a first motor 31, a second motor 32, a rotating shaft 33, a fan blade 34 and a fan frame 36.

An accommodation space 301 is formed inside the shell 30. In this embodiment, the whole structures of the shell 30 are also integrally formed into a single unit. The first motor 31 is disposed inside the accommodation space 301 of the shell 30 and comprises a first coil 311 and a printed circuit board (not shown in FIGs.). The second motor 32 is also disposed inside the accommodation space 301 of the shell 30 and comprises a second coil 321 and a printed circuit board (not shown in FIGs.). The rotating shaft 33 pivots on the shell 30. The fan blade 34 is affixed to the rotating shaft 33. In this embodiment, the fan blade 34 is a blower fan blade. The fan frame 36 has an air inlet side 361 and an air outlet side 362. An airflow channel 363 is formed between the air inlet side 361 and the air outlet side 362.

Each component of the fan 3 is described as above-mentioned. Moreover, the operation of the fan 3 is described as follows. In this embodiment, only the first motor 31 of the fan 3 works first.

First, a first current is generated to flow through the first coil 311 of the first motor 31 when the fan 3 is electrified, for driving the first motor 31 to work. When the first motor 31 is failed (due to the damage of the first coil 311 or other components (not shown in FIGs.)), a second current is generated to flow through the second coil 321 of the second motor 32, for driving the second motor 32 to work. Accordingly, the fan 3 can work stably.

Otherwise, in other embodiments, the first current is generated to flow through the first coil 311 of the first motor 31 first, for driving the first motor 31 to work. The printed circuit board of the first motor 31 is for controlling and detecting how many revolutions the first motor 31 rotates. When the rpm of the first motor 31 reaches a first predetermined revolution, the first motor 31 stops working by the printed circuit board of the first motor 31, and then the second current is generated to flow through the second coil 321 of the second motor 32, for driving the second motor 32 to work. When the rpm of the second motor 32 reaches a second predetermined revolution, the second motor 32 stops working by the printed circuit board of the second motor 32. A sum of the first predetermined revolution of the first motor 31 and the second predetermined revolution of the second motor 32 is defined as a cycle, and the first motor 31 and the second motor 32 is driven to repeat the cycle continuously. Thus, the life span of the fan 3 can be increased. Moreover, the disclosure is not limited to a number of the first predetermined revolution and a number of the second predetermined revolution. In other embodiments, the users can adjust the number of the first predetermined revolution and the number of the second predetermined revolution according to their requirements.

Furthermore, in this embodiment, the rotating shaft 33 is driven to rotate by the first motor 31 or the second motor 32 when the fan 3 is electrified. Then, the fan blade 34 is driven to rotate by the rotating shaft 33, such that at least one airflow F enters the fan frame 36 from the air inlet side 361, flows through the airflow channel 363, and finally leaves the fan frame 36 from the air outlet side 362.

To sum up, according to the disclosure, the first motor and the second motor are coaxial (with the same rotating shaft), such that the thickness of the fan can be decreased. Additionally, the first motor and the second motor work alternatively, such that the life span of the fan can be increased. Furthermore, the fan further comprises a control circuit, for periodically switching the current value of the current flowing through the first coil of the first motor and the current value of the current flowing through the second coil of the second motor. Thus, the first motor and the second motor can be prevented from both working at a high current at the same time, to improve the working efficiency and the life span of the fan.

The disclosure will become more fully understood from the said embodiment for illustration only and thus does not limit the disclosure. Any modifications within the spirit and category of the disclosure fall in the scope of the disclosure. 

What is claimed is:
 1. A fan, comprising: a first motor comprising a first coil through which a first current flows when the fan is electrified; a second motor comprising a second coil through which a second current flows when the fan is electrified; a rotating shaft; and a fan blade affixed to the rotating shaft; wherein the first motor and the second motor drive the rotating shaft to rotate the fan blade when the fan is electrified.
 2. The fan according to claim 1, further comprising a shell, both the first motor and the second motor being disposed inside the shell, and the rotating shaft pivoting on the shell.
 3. The fan according to claim 1, wherein a ratio of a current value of the second current to a current value of the first current is between 0% and 80%.
 4. The fan according to claim 1, wherein the fan blade is a blower fan blade or an axial fan blade.
 5. A fan, comprising: a first motor comprising a first coil; a second motor comprising a second coil; a control circuit for periodically switching a current value of a current flowing through the first coil and a current value of a current flowing through the second coil, and the current value of the current flowing through the first coil being different from the current value of the current flowing through the second coil; a rotating shaft; and a fan blade affixed to the rotating shaft; wherein the first motor and the second motor drive the rotating shaft to rotate the fan blade when the fan is electrified.
 6. The fan according to claim 5, further comprising a shell, both the first motor and the second motor being disposed inside the shell, and the rotating shaft pivoting on the shell.
 7. The fan according to claim 5, wherein the control circuit is for transmitting a first current to the first coil and a second current to the second coil during a first time period, and the control circuit is for transmitting the first current to the second coil and the second current to the first coil during a second time period after the first time period.
 8. The fan according to claim 7, wherein a span of the first time period is a time period when the fan blade rotates from 0 to 100000 revolutions.
 9. The fan according to claim 7, wherein a ratio of a current value of the second current to a current value of the first current is between 0% and 80%.
 10. The fan according to claim 5, wherein the fan blade is a blower fan blade or an axial fan blade. 